Would you consider telling this to the people working at GitHub directly? I’m sure they’d appreciate your evaluation of their skills and talent.
yes I would tell them "you're underpaid, if you can, come to a company that appreciates your talents more".
There are two options, either they are lousy at their jobs, or they are incapable of pushing back against unrealistic demands. Neither is a good indicator of their skill and talent as engineers.
I know I am speaking from a position of some privilege, but I have previously left workplaces that did not allow me to practice good engineering, and I do expect others to do so.